hum - noun

the state of being or appearing to be actively engaged in an activity

an Islamic fundamentalist group in Pakistan that fought the Soviet Union in Afghanistan in the 1980s; now operates as a terrorist organization primarily in Kashmir and seeks Kashmir's accession by Pakistan

a humming noise

hum - verb

• sing with closed lips
• be noisy with activity
• sound with a monotonous hum
• make a low continuous sound

hum - thesaurus

busyness   buzz   hua   humming   seethe   thrum